1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display with a backlight unit capable of emitting light from both of its front surface and back surface, so as to display images on both of a front panel and a back panel of the liquid crystal display.
2. Description of the Prior Art
Liquid crystal displays (LCDs) are widely used in digital cameras, PDAs, vehicle satellite navigation systems, computer monitors, flat panel TVs and so on. The LCDs are composed of two transparent glass substrates with a liquid crystal layer positioned between the two glass substrates. Since the LCDs cannot emit light by themselves, a backlight unit is required to be installed at the backside of the LCD to provide light source for displaying images.
The backlight unit uses a light guide plate to guide light emitted from a self-emitting light source (such as fluorescent lamps or light emitting diodes) to the elements such as a reflector and a diffusion sheet to brighten the light and generate a uniform plane light source. Sometimes, in order to make the light has special optical characteristics, an optical film is installed in the backlight unit, for example a prism sheet is often installed on the diffusion sheet to focus the light and increase the brightness on the front surface of the backlight. In addition, special patterns are also formed on the light guide plate to adjust the light according to product demands.
Since the quality of the backlight unit will no doubt affect the display quality of the LCD, and the backlight unit occupies a very high percentage of production cost or power consumption of the entire LCD, it is very important to reduce the production cost and the power consumption of the backlight unit in development of the LCD application.